A Complete Guide to Take-Down/ Reassembly of the CZ-52

We get a slew of calls and emails about the CZ-52, probably due to the bargain prices they sell for on the used/import market. So a full article on the subject was warranted—and, besides, the CZ-52 is a very interesting pistol from several aspects. Would you believe 1,600 fps from its original 7.62 x 25 chambering? How about its being a single-action with a decocking feature like the current crop of DA/SA semi-autos? And why wasn’t it based on a John M. Browning design? Aren’t all pistols?

Certainly most are, but the Czechs decided to "borrow" the design of the German MG42 for the action of the CZ-52. Technically, it operates on a "roller-delayed blow-back action." We’ve reported on this kind of action here recently (see "The CETME Rifle," May 2003) and in the past (H&K MP5, October 1993), and this type of action is found in the H&K 91, 93, and P9 Pistols.

The difference in configuration between the long guns and the CZ lies in where the rollers are positioned and how they interact with the rest of the gun. To be specific, the CETME and MP5 rollers are in the bolt. In the CZ, they’re linked to the barrel locking it and the slide together. The roller cam retaining the rollers in the locked position seats in a frame lug.

When the pistol is fired, the rollers are disengaged after about 1/4-inch of recoil; the barrel lug engages the frame; and the slide continues to the rear, extracting and ejecting the spent case. While the pistol is a single-action, its firing pin has an automatic safety catch that prevents firing until the trigger is pulled. The frame-mounted safety itself has three positions. Lowest is the "fire" and exposes ared detent to alert the shooter to that fact.

The middle position places the safety into engagement with the trigger bar and rebound notch of the hammer. In this mode, the pistol is cocked and locked and can be safely unloaded. At its uppermost point, the safety enters the hammer rebound notch to provide the decocking function. A word of advice: When you’re handed a CZ-52, check out the safety function in all three positions with unprimed dummy rounds.

It’s very possible there has been excessive wear or breakage and the mechanism or parts of it will have to be replaced. Among these will be the firing pin, The one pictured here is in 7.62 Tokarev caliber and is available from Century Arms International which will undoubtedly break under dry-fire conditions. A broken firing pin will, as you’d expect from the previous explanation concerning the safety functions, defeat the automatic-safety catch.

If so, the hammer could fall from a blow to its rear and the pistol could discharge should alive round be in the chamber. Now gather up a couple of drift punches, a pair of needle-nose vise grips, and we’ll tear down this pistol.

Basic Disassembly The chamber is empty and the magazine has been removed. Cycle the slide once. Keeping your finger off the trigger, move the safety lever to its uppermost position. The hammer will fall. Pull down on the take-down tabs located in front of the trigger guard on both sides of the frame. This will allow the slide assembly to move forward and be lifted straight up off the frame. Invert the slide assembly, and insert a flat-blade screwdriver or the magazine base plate in the roller cam slot.

Get a firm hold on the slide, and move the cam forward toward the take-down notch to disengage the rollers from their slide recesses. As an alternate to the screwdriver or magazine base, you can insert a 3/16-inch punch in the hole under it to move the cam and disengage the rollers. Tilt the breech up slightly, and remove the barrel/ recoil-spring assembly from the slide. The spring is quite strong.

You have now reduced the CZ-52 to its four fundamental assemblies, but, of course, that’s not enough for our purposes here. Detailed Disassembly No "factory" exploded diagram exists for the CZ-52, although there is a well-executed exploded drawing that can be found on numerous internet sites. We believe this drawing may have appeared in one of the NRA’s publications, but they tell us they do not own the copyrights to it.

In any case, to avoid any possible conflicts, we are not including the drawing here, but you’ll be able to find it easily by typing "CZ-52 Drawing" into your favorite search engine (or going directly to http://www.mek-schuetzen. de/Blueprints/cz52part.jpg or Gorge/4653/cz52explo.jpg). The part numbers referenced in the following paragraphs refer to this drawing. Begin the detailed disassembly by turning the recoil spring off the barrel.

The roller cam retaining pin (#29) is drifted out in either direction with a 3/32-inch punch. Note: This pin is staked in and has to be restaked when and if the rollers (#30) are ever replaced. Place the slide upside down on your bench. Locate the firing pin retractor lock (#7). It’s semicircular and shouldn’t be hard to spot. Use the 3/32-inch punch to push down on the retractor, tilt the slide, and tap its rear end on your work surface.

The firing pin will slide out, unless it has become trapped inside by fouling. Remove the retractor lock and its spring (#8). The extractor pin (#4) is driven out downward with the 3/32-inch punch to free the extractor (#3) and its spring (#5) and move along to the frame. Remove the grip panels (#10 and #11) and the grip-retaining clip (#12). Now you’re going to need the needle-nose vise grips.

The hammer spring (#16) isn’t just strong—it’s very, very strong—complicated by the fact that it’s one of the components holding in the magazine catch (#23). The other is the hammer strut (#17). Ready for a struggle? Fine. Grab onto the magazine catch with the needle-nose vise grips (you have taped the jaws, right?) and push it toward the top of the frame to compress the hammer spring. Keep pushing upward and inward until the catch can be separated from the frame.

It must be depressed when removing the firing pin and spring.

Above left and The right-hand photo shows the cam to the rear as it would be when the barrel has been reinstalled in the slide. Now open and close your hand a few times to work out any finger, palm, wrist, or forearm cramps you may have experienced. Once you’ve recovered, the hammer strut can come out, and you can turn your attention to the hammer-pivot nut (#15). It’s staked in and may resist your efforts to remove it with a 6mm socket.

Having prevailed over the hammer spring, you will do the same with the pivot nut. You now drift out the hammer-strut pin (#18) right to left and remove the hammer (#13). The 3/32-inch punch gets called on again to drift the trigger-pivot pin (#44) and sear/ejector-spring pin (#33) right to left half-way out. Why only half-way? That’s all the farther you have to move those parts to get the sideplate off, and because they retain the sear spring (#34) and trigger-return/disconnector spring (#45).

With the right side of the frame facing upward, tap below the sideplate on the magazine well and even with the bottom of the trigger guard. This will cause the plate to lift up enough on its own to be taken off and expose the pistol’s innards. There can be seen the trigger bar/disconnector (#42). Lift it off the trigger-bar link pin (#43), unhook the trigger-return/ disconnector spring from the pin and counter-clock the spring out of the gun. The trigger (#41) may come off the trigger pivot pin with it.

If not, remove the trigger as your next step. Moving upward to the rear of the frame, take time out to memorize the positions of the sear, sear spring, and ejector. Push the sear/ejector-spring pin out the rest of the way, but leave the punch in to retain the sear (#32) and sear spring. To remove those parts, slowly withdraw the punch and control the spring’s urge to escape. In this process, you will also free up the ejector (#2). Next target: the take-down latch/ hold-open pin (#39).

Drift it right to left while holding your thumb over the latch. Keep pressing down as you pull out the punch, ease off on the latch and lift it out. This will free the hold-open catch (#19) as well. Grasp the catch by its front end, lift and slide it from its notch in the left rear of the frame. Stay on the left side. Turn the safety lever (#31) to 12 o’clock, and pull it to the left while restraining the hold-open/ safety-detent spring (#20). A leg of that spring fits in a milled slot in the frame.

Note how it fits for reassembly purposes, which is performed in reverse order. Reassembly Tips The short leg of the sear spring rests atop the sear. The long leg extends toward the front of the gun and into its frame recess. A jeweler’s screwdriver is a handy tool to have when working in these tight quarters. I hope you took my earlier advice to memorize the installed positions of the sear, sear spring, and ejector. If not, you’ll regret it about now.

Those parts should be reassembled on a punch being inserted into the frame, held together, and the punch pushed out with the sear/ejector/spring pin. The center of the coils on the trigger/trigger-return/disconnector spring is placed on the trigger pin.

Correct reinstallation is discussed in the "Reassembly Tips" section of the article. The hooked end of the spring attaches to the trigger bar. The other end rests in the trigger body. The trigger bar rides in a cutout in the sideplate. When replacing the plate, pull the trigger slightly and put the front of the plate in the frame. Lower the back end of the plate into place and check the trigger bar for freedom of movement by working the trigger back and forth.

To replace the hammer pin, locate its notch in the frame, and align that with the notch in the head of the pin. The body of the pin is also notched where the trigger bar rides. As you push the pin in, push the bar down. End result: The bar has to be seated in the notch in the body of the pin when the pin is fully installed. The firing pin must be installed in the slide as follows: The retractor lock has a semicircular and a flat portion. The flat portion runs parallel to the long axis of the slide.

The flat of the firing pin mates with the upper flat of the retractor. The roller cam has a circular section that slides over the barrel and a tongue recessing into the bottom of the barrel. The roller cutouts are also located on the underside of the barrel. When you slide on the cam, its rear has to end up flush with the front of the roller cutouts, the rollers are placed in their cutouts, pushed as far as possible to each side, and the cam moved to the rear of the barrel before reinstalling pin #12.

What’s so simple with other semi-autos isn’t with the CZ-52. Reinstalling the barrel/recoil-spring assembly in the slide can develop into a major pothole on the road to success. Select a punch that fills the hole in the bottom of the roller cam, and secure the slide upside down between padded vise jaws. Slip the recoil spring on the barrel. Insert the punch in the roller cam, and push the cam toward the muzzle. This will begin to compress the recoil spring and the barrel should enter its opening in the slide.

If it doesn’t, the spring has gotten in the way. Slack off and give the spring a quarter of a turn. Keep everything moving toward the muzzle with light downward pressure. When the rollers enter the take-down notch just forward of the ejection port, the barrel should drop down and the rollers will be flush with the bottom of the slide. When that happens, pull the punch, the barrel will move to the rear under spring pressure, and the rollers will seat in their slide recesses.

In case you missed mention of it earlier, make a notation in your CZ-52 file: The only parts of the pistol considered fragile for long-term service are the firing pin and sear. ■